Uploading a copyrighted book like The Simple Path to Wealth to a public GitHub repository without the author's permission is a violation of copyright law. While GitHub is generally responsive to DMCA takedown notices, these repositories often pop up faster than they can be removed. Downloading these PDFs exists in a legal grey area depending on your jurisdiction, but it is, effectively, piracy.
Many developers who love The Simple Path to Wealth have built open-source tools based on its principles: the simple path to wealth pdf github
Financial markets change. Tax laws change. The first edition of The Simple Path to Wealth focused heavily on US-centric strategies. Later revisions (and the author’s blog) have updated nuances on international holdings and tax efficiency. The random PDF from 2016 on GitHub will cost you more in missed tax strategies than the $15 paperback is worth. Uploading a copyrighted book like The Simple Path